A SAS (serial attached SCSI—small computer system interface) protocol network can include multiple storage clients and array systems coupled to one another through one or more SAS switches. A SAS switch can access physical ports on the array systems. By accessing the physical port, the SAS switch can interface with a PHY (physical) port and discover a logical unit associated with the physical port.
Through the PHY ports, the array systems identify themselves to be expander devices capable of zoning. The SAS switch can additionally identify addresses for each of the PHY ports. Each physical port can include a single address utilized by the switch and other devices on the SAS network to identify a location of the PHY port and a logical unit associated with the PHY port.
The SAS switch can include the addresses of the PHY ports in an address table and proceed to manage access to the PHY ports of the logical units through a process called logical unit masking. Logical unit masking is a process where the SAS switch masks or hides an address of a PHY port associated with a logical unit in the address table. The SAS switch shares the address table, including the masked addresses, with storage clients coupled to the SAS switch and the storage clients use the address table to identify addresses of PHY ports which are available to the corresponding storage client to access.
To support logical unit masking, the array systems included in the SAS network fabric employ a common network protocol which utilizes the PHY ports. This can lead to costly overhead for the SAS switch, the storage clients and the expander devices. Additionally, maintenance for the network can be increased due to the large infrastructure and increased points of failures which may be present from relying on multiple PHY ports on multiple devices on the SAS network.